<div class="doc-item" id="doc-1043"><h2 class="doc-item-name">merge-with<span class="namespace">(clojure.core)</span></h2><ul class="var-arglists"><li>(<span class="var-name">merge-with</span> f &amp; maps)</li></ul><div class="var-docstring"><p>Returns a map that consists of the rest of the maps conj-ed onto
  the first.  If a key occurs in more than one map, the mapping(s)
  from the latter (left-to-right) will be combined with the mapping in
  the result by calling (f val-in-result val-in-latter).</p></div><div class="var-source"><pre>; clojure/core.clj:1643
(defn merge-with
  [f &amp; maps]
  (when (some identity maps)
    (let [merge-entry (fn [m e]
			(let [k (key e) v (val e)]
			  (if (contains? m k)
			    (assoc m k (f (m k) v))
			    (assoc m k v))))
          merge2 (fn [m1 m2]
		   (reduce merge-entry (or m1 {}) (seq m2)))]
      (reduce merge2 maps))))</pre></div><div class="license"><p>Copyright (c) Rich Hickey. All rights reserved.</p><p>The use and distribution terms for this software are covered by the <a href="http://opensource.org/licenses/eclipse-1.0.php">Eclipse Public License 1.0</a>, which can be found in the file
          epl-v10.html at the root of this distribution. By using this software
          in any fashion, you are agreeing to be bound by the terms of this
          license. You must not remove this notice, or any other, from this
          software.</p></div></div>